For joining the ends of cables and the like there is a need for a secure lock which allows quick and easy engagement and disengagement and yet is relatively simple in design. In addition it is advantageous if such a lock can only be disengaged by special manipulation with the hand or hands such as requiring the use of both hands before disengagement can occur or requiring only the squeezing of a member to allow disengagement such as is necessary in parachute harnesses. It is the primary object of this invention to provide a simple yet secure locking device for cables and chains and the like which can also be adapted for use in special circumstances having high safety requirements.